Drilling machine



Sept. l21 1926. t, 1,600,847v

I A. E. ROBINSON ET AL l I DRILLING MACHINEl Filed June 27, 1924 5 Sheets-Sheet l MM n my vMM/mw- A.E. ROBINSON ET AL l DRLLING MACHINE l Filed Jugez?, 1924 5 sheets-sheet 2 Sept. 21 1926.

. 1,600,847 A. E. ROBINSON ET AL DRILLING MACHINE Filed June 27, 1924 5 Sheeizs--Sheels 5 sept. 21 ,1926. 1,600,847

A. E. ROBINSON ET AL DRILLING MACHINE Filed June 27, 1924 5 sheets-Sheet 4 rl-Q l5. 55 45 6% spn 21 ,1926.

Y 1,600,847 A. E. ROBINSON ET AL DRILLING MACHINE Filed June 27,' 1924 5 sheets-sheet 5 Iig 2 2 zz I 'za ""3 .n zzn lv 'L21 l @4l 232.

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\6% 1s IU l INVENTORS.

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-Illl Patented Sept. 21, 1926.

UNITED sr Freelan? TES ei-ENT] einer. L

lAIQEEET E. ROBINSON AND AUGUSTUS M. sosA, OE CINCINNATI, OHIO, AssIGNoEs To THE AMERICAN TOOL WORKS COMPANY,Y OECINCINNATI, OI-IIO,A CORPORATION OE OHIO.

- DRILLING Application filed June 27,

Our invention relates to drilling machinery, especially to that type known as radial drilling machines.

Itis the object ofour invention to prolvide new and improved .meansv whereby theV for the drill-arm and novel-means for operating the same including a power connecting andV disconnecting couple and a switch for controlling the operation of the same, and afinanual control for said couple and said switchso related as to arrange said couple for connection and to operate said switch in sequence; further, to provide auto-matic means Jfor disconnecting said couple; Jfurther, to provide clamping means for the drill-arm and novel means for operating said clamp including an electricmotor and novel means for operatively connecting saidelectric motor and said operating means and Jror disconnecting' the `sameyand, fur- 'ther,'toprovide clamping. means for the l y 'taken in the plane of theline 17-17 of drill-arm including an eccentric, a crank for Y operating the eccentric and novel means for operating said crank. 1 l

The invention ywill be,` further readily' understood from the following description and claims, and from` the drawings, lin

' which latter Fig. 1 isa' side elevation of a drilling machine having ou'r invention embodied therein, partly broken away.

. Fig-2 is la` plan view of the same, partly broken away.

8 isa vertical section of a detail of a portion of the clamp operating mechanism, taken on the line 3-3 of Fig.' 2.

Fig. 4 is an end elevation'oi a drilling machine having our inventionapplied thereto.,-partly broken away. f' 7 Fig. 5 is a horizontal sectionof a det-ail .ofthe same, taken on the line55 of Figli.

Fig. 6 is a detail oiithe knock-out mechan- 1924. Serial NO. 722,857.

ism, shofwn of Fig. 9.

Fig. 7 is a horizontalsection of the electric switch, taken on the line 7-7 of Fig.` 4.

Fig 8 isa 'plan view. of our` improved dei vice, part-ly insection on"y the yline8--S of Fig. 1.

Fig. 9 is anenlargedplan detail of the same. i

Fig. 10 is a vvertical cross-section of the same, taken on the line 10-10 of Fig. 9,

roller and its support.

Fig. 11 is a detail of the same, shown in horizontal section vin .the plane .of the irregular line 11--11 of FigflO.'

ig. -12 is a similar view of the vsame in assumed Position. i i Fig. 13 is a detail of thev same, taken in the planeof the line'13-#13 of Fig. 11. -F1g;l 14@ is a vertical section of the clamp-l `partly in .section on theiline `6--6y including a vertical section Vof the knock-out i ing mechanism, taken on the line 1%-14 of FigS.V Fig. A15 is a plan ating means therefor in unclamped position. Fig. 16 is asimilar view, showing the parts in clamping position. y Y

Fig. ,17 is a detail in horizontal section,

f Figs'19 is a` cross-sect-1on, taken on the line V19,-19 of Fig. 2, showing-the operating handle for our improved device. l

Fig. '20 is a detail of thefsame, taken in section on the line 20-'20 of Fig. 19. i Fig. 21'is a plan View'r o'lf'our improved device,l showing a modification, partly broken away, 'and partly in'section onthe line 214-21`of Fig. 2;.Land, V f

Fig'. 22 .is a vertical section' of" the same, taken in "the plane' of thev irregular` rline zat-caofrigaifi A I' 7e Yhave exemplified Aour Vinvention on a drilling machinecomprising a base 21,'rom which *ar 'stationary post 22 "extendsupwardly, faboutwhich 'there is a rotatable-'column view, partly in section, Ishowing the clamping-means and the operthe column and is adjustable to elevation '.Lthereon by slide connection between its bearing y26erandv the outerf peripheryy of said column, the 'adjustment being usually effected by means of an adjusting screw27 having threaded connection 'with a suitable nutonjth'eQarm,v relative rotation between the screw and'nut effecting' raising or lowering of the drill-arm.

The drill-arin carries a suitable drill-head 31 adjustable laterally thereon on guideways 32, extending lengthwise of the drill-arm,

the 4adjustment being exemplified as ef- V A byhandles 85, 36, on the'drill-head.

f A suitable .drill-spindle 37 is journaled on Vfected by a suitable rack 34 on the drill-arm,

with which a suitable pinion mounted on the drill-head meshes, the pinion being suitabiy operated, asbyatrain of gearing operated the .drill-head and is Varranged to have a lil) suitable drill 38 secured thereto, suitable means being provided for axially feeding ,A Athe drill-spindle.l

In the present exemplification, the column is rotatable on the base for the purpose of adjustment of the drill-arm into suitable' of a gear-box 73 ona bracket 74 extending radial positions with vrelation to the'base in well-known manner.

Y The drill-arm is arranged to be clamped in suitable adjusted positions, effected in the present instance by clamping the column to the hase, the column has a. spiit-bearing 41 about a lower journal-part 42 of the post.

` The Vsplit-beariiig is arranged'to be clamped about the post by means of an eccentric 43 on a shaft 44 journaled in bearings 45, 46, located in lugs on said split-bearing, at one gside'of the split thereof. A` linkv 47 has a bearing 48A about said eccentric and extends Y lthrough an aperture 49 in a cheek 50 formed as a lug-at the other side of said split, and adjustable with relation thereto by means of a nut 51 threaded over the threaded end` 52 of said link, a washer 58Y being shown between said 2'cheek and said nut. (See Figs.` 14 and 17.)A Vf Y The eccentricl is arranged vto-bev rotated, shownv accomplished* in. the present exempliiication by Van arm 55. secured to said shaft, and means for swinging said arm.

vThe connection between said) arm and said shaft is preferably adjustable, as by providing a cone-clutch connection 56 between them, with a nut 57 received over the threaded end 58 of said shaft for clamping said arm to said shaft. (SeeFig. 14.)

1 The eccentric is operable for drawing said Y split-bearing about ythe post and Vclamping it tothe base, the locking relation being preferably such that' a right line, exemplified at C, Vdrawn *through ythe highY 'ing and disengaging couple,

e point 62 of l, the' eccentric-andthe axis. of rotation `63 of high Joint is moved vawa from said ri ht a l line will cause an unclamping movement in` therclamp-bearing, due to the natural re-v siliency in the metal of said bearing, for releasing itsclamping hold upon the post. The extent of such movement is optional, the unclamping `position of the eccentric being indicatedy in dotted lines in Fig. 15. Such movement of the eccentric is-:accomplished by va movement. of the arm 55- into the position shown inF ig. 15. The position of the high point of the eccentric with relation to the axis of rotation of the shaft44 'is then as siiown Ain 15. l

. The rotation .off the eccentric/is inV the present Ainstance accomplished Vby a crank comprising a crank-pin 67 and a crank-arm 68 having an axis of rotation 69, and exemplified as rotated byV a: gear 70, rotatable about a stud-shaft 71 fixed in a hearing72 from the column. The arm is exemplified as ixed'to va hub 75 .extending from said :ge-ar, being, for instance, keyed thereto bya key 76, and held-to said hub by a flange 77 on said stud-shaft. (See Fig. 18.-)

A link 78 is articulated about the crankpin at one of its ends, and is at its other end articulated withthe arm 55 by a pin 79.

This gear is shown in F igs. .1 to 20 inclusive as a worm-wlieel v`and as engaged by a worm 81 fixed to a shaft 82, journaled in bearings 83, 84, lof said `gear-box. (See Figs-5i and 18.) The shaft 82 is exemplified 'asl rotated by the armature-shaft 85 .of the 'electric motor 86,-mounted on the bracket A A power connecting and .disconnecting Y couple, exemplified asa clutch 91 is located nection 94 with thel shaft 85, the collar-93 being movable lengthwise on saidshaft. (See Fig. 5.) Saidclutch is exemplified as aA tooth-clutch, the teeth .of which are on the proximate ends of said collars, said collars representing` the members of a power engagwhich couple may, however, be of other form, and be any suitable power engaging or disengaging couple for connecting the power of a motor with theV cra-nk, Y V

soVv

Vthe links.

M A switch 101 is located in a switch-box 102 fixed to apad 103 on the column, and

Y is exemplified as' comprising l a rockable motor. (See Figs. 4 and 7.)

Means are provided for operating the power connecting and disconnecting coupleV or clutch and the switch. These means are shown as including manual means for operating the couple and the switch in sequence in the order named, in order that engagement in the clutchshall take place prior to `a power application in the motor suiiicient to speed up the motor, which'would make clutch engagement diiicult, or the clutch is placed in relation for readily engaging upon initial rotation of the motor, as ywill be hereinafter more fully explained. Y

The manual means for operating the clutch and switch are exempliiied as aV pair of links 111,112, the'link 111 being in the form of a rod having operative connection with the clutch, and the link 112 having operative connection with ythe switch. (See Figs. 2, 4 and 8.) These links y.are respectively articulated by articulations 113, 114, with arms 116, 117, fixed to an upright shaft 118 extending lengthwise of the column and journaled in bearings 119, 120, on the column. The shaft 118 has spline-key and groove connection 121 with a bevel-gear V122 moving with the drill-arm, and the hub of which is journaled in a bearing'123, on a bracket 124 fixed to the bearings 26 of the drill-arm; 'A bevel-gear 125 meshes with the bevel-gear 122,. and is xed toa shaft 126 journaled in bearings 127 on the drill-arm.

A spring 131 surrounds said shaft, one end of the spring being received in a hole `132 lin one of the bearings 127, the other endof i the spring vbeing received ina hole 133 ina collar 134, -adjustably fixed to said shaft by a set-bolt 135. for adjustingthe tension of the spring. The spring normally retracts A'bevel-gear 138 is lixed to the shaft 126, and meshes'with a bevel-gear 139 fixed. to a shaft 140. journaled in bearings 141 and extending rthrough the drill-arm. This shaft has a bevel-gear 142. fixed thereto', which meshes with the bevel-gear 143` fixed to a l drill-head n swinging movements of the handleinay be jliniited'by striking the lug 156 and a lug 157D Afixed thereto.l

See Figs. 1, 2, 3, 19 andy ,to move laterally with .thedrill-head. The

hub 153 of the handle is shown. provided.

with anannulargroove 154, in which a bolty 155 threaded into a lug 156 on the drill-head is received, for holding the handle and the in= lateral arrangement.

on the drill-head.'

A rock-shaft 165 is joumaled in gaming 166 in the bracket'74, and has an arm 167 A block 168 is swiveled to said arm, as on a stub-169 in a bearing 170 of said arm, held to said bearing by a' collar 171 and set-screw `172. (See Figs. 10y and 18.) v,

The block has a triggerV 175 pivoted thereto on a pin 176,the trigger having a latch 177 and a heel}178. (See Figs. 11, 12 and 13.) The rod has a latch-piece' 181 lixed thereto. The Vlatch and latch-piece having abrupt engaging face-5182, 183, for causing movement of the latch with the latchpiece, duringmovement of said rod in one axial direction, thefsaid latch and latchpiece being provided with coacting inclined faces 184, 185, for enabling thelatch-piece to be received under the latch when said rod is moved in the'opposite axial direction.` A stop 186 on the latch coacts with the block 168 to maintain thejlatch in engageable relation with the latch-piece. g *f lThe. latch ,is resiliently held vfor `such engageable relation by means -of 'a plug'188, in a bore 189vof the heel 178 of the trigger, the plug' being spring-pressed toward, the

rod by a spring 190 in said bore, and held therein by a threaded plug; 191. The rod'is provided with a'seat 193, shown as a flataxially undersaid plug by application-of sucient .forcefrom' the handle. See Figs. 10,11 and 12.)v .1' v A'trip is provided for automatically disengaging the latch during" movement ofthe rod in clutch-engaging direction, so,as to permit a further movement of the links/in The n order to operate the switch.'v -Thus afstop 201 is provided, shown asa set-screw: adjustable in afthreaded hole in a. shank 202 extending from and fixed to the bracket 74.r and held in adjusted positions'by means of a jam-nut 203. This stopfis. arranged to be'V engaged vby the heel `1785of the trigger,

whereby the latch is swung on its pivot for l releasing the-latch-piece, enabling continu.- ing movement in the samedirecti'on of said rod. i

.Arms 206, '207,` are alsolixedto said rock-il,`

shaft 165 and are provided'with pins 208 on which rollersA v209 are located, y lthe rollers being received in an annular groove 210 of Ythe movable member ofthe clutch for actuating the same. (See Figs. 9 and Y10.)

VThe arm 206 alsohas a plate ,211 fixed thereto, VVwith which y a resiliently acting plunger 212 is arranged to coact, for urging the'arins in opposite directions, for maintaining theV clutch in engaged relation yor disengaged relation,accordingto Vthe directionsV l of movement of said movable .clutch-member,

and Lpreferably for completing respectively the clutch engaging and clutch releasing movements of said arm. (SeeFigs. 9 and 10.) For this purpose the plate is provided with Vnotches 215, 216, with the walls of which the lplunger is arranged to coact. The coacting` faces of the notches and of the plunger are incl-ined for causing the plunger to automatically move into said notches respectively after the apex 217 betweenitlie notches .passestlie apeX 218 of the plunger. The plunger operates in a bore 220 of a barrel 221, supported on the gear-box, andris providedl with a stem'222 reciprocating in a hole in a plug 223 in the threaded end Aof said bore, a spring 224 surrounding 4said stem between said plug and said plunger for normally Vurging the plunger toward said plate.

vThe arm 206 vis also provided with a contact part, shown as a roller. 226, journaled on a shoulder screw 227, threaded into said arm. (See FigsfS, 9 and 10.) c

-V 'Means are provided ,for automatically disengaging the clutch or power connecting and disconnecting couple, exemplified asv `Yknock-out arms, 231, 232, on a knock-out plate 233, rockable about a journal portion V23tof the gear 70, and held to said journal portionY by the hub of the crank-arm V68. (See Figs; 8 and 1S.) Y

Y Resilient yield is permitted to the knockout arms upon contact with the clutch-arm toy avoid shock and jar'between the parts, thisresilient yield being effected by'aspring Y (See Figs.8 vand 21.)` Thel respective ends ofthe spring are received about a pin A238 Von said knock-,out plate and a pin 239 on the gear 70, the said gear being -further provided with limiting pins 24:0, 241. .The knock-out plate is-arranged to impinge against the pin 240 for defining its normal position, and the pin 2111 limits the yielding movement of the plate, and acts as a stop Atherefori'to definitely control the clutch release. Y i- In operation, when it is desired to clamp or unclamp lthe radial drill-arm, the operator, whosefpositio'n is in front of the driil- 'head, manually operatesvf the handle 151 for causing movement of the links `111, 112.,

inthe direction of the arrow a.

(See Figs. 4, 8, .11 and 12.) This operationy simultaneously mov'es'both links, the first eiiect Yof which, is, inthe present exemplific'ation,

for the latclivpiece 181 to carry the latch'177 with it in itsmovement, swinging 'the lever or arm 167 and rocking the shaftl for moving the movable member' of the clutchtowardits mating member so as Vto cause ysubstantially clutching relation. This same movement moves the arm 206 and the automatic locating plate 211 for causing the apex rr217 thereof to pass the apex 218 of the plunger, whereby the spring-pressed plunger causes further movement in the same direction of said arm andsaid clutch-member.- (See Figs. 9 and 21.)

rThe clutch is exemplified as rotating in the direction of the arrow7 b in Fig. 5. The clutch-teeth preferably have coacting abrupt faces 24:8 at one of their respective sides and inclined faces 244 at the other of their respective sides, whereby the teeth of the mov-v able clutch-collar are arranged to slide into the tooth-spaces between the teeth of its mating -clutch-collar when Contact has once been made between the ends of said clutchteetli.

This sliding movement may be effected by the interaction of the spring-pressed plunger 212 and its coacting plate`211.

There is spaced relation between the elec- -tric contacts on the rockable member of the eiectric switch, as exemplifiedat 246, 7), and its coacting contacts, this spaced re-y lation being provided for the purpose of enabling the power connecting and disconnecting couple, exemplified as the clutch, to be placedin'coactive relation for engagement vpriorto substantial electrically connected relation to the electricv switch, in order that such coactive relation for engagement in the clutch may be effected prior to substantial power applicationby the motor for.l performing the clamping function, although not necessarily prior to initial rotative impulse is imparted to the motor, whereby shock to the parts Sand shock and wear bel tween the clutch-teeth is avoided. Y

vThen such "clutch engagementf'has vbeen effected and effective power is being aplyond the spaced relation therein for full vcontact in said switch, in'oi'der'to supply full currrent to the eiectric'inotor for operation of the same. f Y

The crank-arm is by suchrpower application rotated, vexemplified as throughout a halt revolution,whereuponthe clutch is disengaged, instanced as accomplishedby the knock-out arms engaging the arm 206, theI spring 237 avoiding shock totheparts., and the pin 2li-1, limiting the yielding movement of the knock-out arm so as to 'cause delinite relation of clutch disengagement to angle of crank-arm rotation. Such movement carries theV apex 217 of the knock-out lplate across the apex 2180i the plunger, 'the spring-pressed plunger completing disengagement of the clutch. (SeeFigs. 9 and As soon as clutch disengagement takes place, rotation of the crank-arm ceases, regardless of continuation of power in the electric motor, andlregardless ot' switch relation. Switch release is effected by release of the operatorshandle by the operator, causing the spring 131 to return said handle to normal position, wherebyk said links are also returned to normal positions. During reverse movement of the link or rod l111, the Vinclined faces ot the latch rand its latchpiecre coact forv raising the latch and permitting thevlatch-piece to bereceived behind the latch, thereby resetting said parts Jfor operation for the next clamping or unclamp-r ing movement for-the operating clamp.

The release movement ot the clutch is automatically effected `in orderto provide definite relation 4between the operating means and the clamp at the clamping and unclainping moments of the clamp.

The clampingV relation ot the clamp is vpreferably such that a Vright line drawn through the .axis of rotation of 'theeccentric and the high point of the eccentric is'parallel with the line of clamping power be'- tween the cheeks at the respective sidesA ot the split-bearing, being exemplified as par allel with the link a7, as exemplilied by the dot and dash line-c. (See Figs. 16 and 17.) This relation insuresV a# maintenance of clamping action of the clamp tor'maintaining the radial drill-arm in adjusted radial position. A

rThe means'or operating the clamp are also 4preferably such that a right line, exemplified by the dot and dash line cl, (in Figs. 15 and 16) will intersect the axis of: rotation ot thecrank-arm and the axis Ot' the crank, and bel substantially parallel with the link 78, preferably-also 'bisecting the axisro't articulationrb'etween said link and the arm 55. The axis of said crank is pret#v erably at one side otthe axisl otrotation of the crank-arm and bisects said right line when the eccentric 1s Vin clamping relation,

and bisects said right .line at the other side,V

of said axis of rotation when said eccentric is in unclamping relation.. -v

The crank is preferably inv dead-*centerposition with relation tothe clamp-arm when the clampis in clamping position, and Vis shown in dead-center f position when vthe clamp is inV clamping relation and 'in unclamping relation:` Y

Y ln the present exemplication, the vclamping action and the unclamping action arev alternately etected by successive manual actuations of the handle151, and by successive operations of themeans described for` actuating the crank-pin 67. At a given half revolution of the crank-arm 68, the clampis moved froman unclamped relation, such as shown in Fig. 15, to a clamped relation, such as Yshown in Fig. 16',- and at the next half revolution ot the crank-arm 68 in the same direction, the clamp is moved from a clamped relation,v such as shown in Fig. 16,

to an lunclamped relation, such as shown in Fig. r15. The operating ,1inks"111,'112,V are, tor initiating each of said movements,

moved in the same direct-ion, as exemplified by the direction of the arrows a inV Figs. l andv 8. The arm reciprocates betweenthe positions sho-wn in Figs. 15 and16;

I have in Figs. 1 to 2O inclusive exempliiied av worm and vworin-wheelv as rotating the crank-arm. It desired, this gear connection may take vthev form illustrated in Figs. '21? and'22,-in which similar parts are represent` ed byv similar `reference numerals, but the gear connection is shown as a train 'of bevel and spur gears. f' l i y For example, the clutch-collar 92 is fixed to a shaft 251, journaled in a bearing 252 on the gear-'box pinion V253V tixed thereto, which mesheswith a bevel-pinion. 254, ixe'd to .a shaft 255,' journaled in ai bearing 256 on saidbracket.

This shattrhas a bevel- Thl's shaft also carries a spur-#pinion 2,57"

'lubricant thereto andV to their journals.

Havfng thus vfully describedvour invention.what we claim 'as1new,\ and desire "to secure by Letters'fPatent-,iszx E 1'. `lna drilling machine, the combination ot a. base, Va'. toolarm adjustable to radial positions thereabove, a clamp for clamping saidI tool-army in adjusted position, means V'lor operatingV said clamp comprising. anr

electric motor, a power connecting and dislll) connecting couple operatively disposed loe-v tweeirsaid electric motor and said clamp,

`and a power controlling switch for controlling actuation orn said electric motor, nsaid couple including a Amovable member, a controlmember., and mechanical connections between said' controlmember `and said mov-` able member and between said control-inember and saidA switch so constructed and .ar-

rrang-cdas to arrange 'said couple tor connection and to operate said switch for power actuation. Y

2. In a drilling machine, the combination oi aMbase, a tool-arm adjustable to Iradial positionstliereabove,a'clamp for clamping 'pio said tool-armV in Yadjusted position, means tor operating said clamp comprising an Lectric motor, a power connecting vand disconnecting couple operatively disposed between said electric motor-,and said clamp and a power controlling switchfor control` ling actuation of said electric lmotor and a V'control-member for, arranging said couple for 4connection and-for operating said switch for Vsubstantially full power-actuation in Y ,i the sequence named.

3. In a drilling machine, the combination Aof abase, a tool-arm adjustableto radial positions thereabove, aclainp for clamping vsaid tool-armgi-ii adjusted position, means for operating said clamp comprising an" said lswitch 'for substantially full poweractuation-in the sequence named, and -means for automatically completing connection insaid couple.

if In a drilling machine, the combination `of a'base, a tool-arm adjustable to -radial positionsthereabove, a clamp for clamping saidtool-arm in adjusted position, means for operatingy said clamp comprising 'an electric motor, a power connecting-and disconnecting coupl-e operatively V- disp'osed between said electric motor and said clamp, and -a power controlling switch for con.

trolling actuation of said electric motor, a

' control-member for arranging said couple for connection and for operating 'said vswitch for lsubstantially -ull power actuation inA the'sequence named, and means tor automatically disconnecting, said couple.

5. In a drilling machine, the combination of a base, a tool-arm adjustable to radial positions thereabove, la clamp for clamping said ytool-arm inadjusted position, means for` operating :said clamp comprising -an electric motor,a mechanical power'connecting and' disconnecting couple comprising xa movableinember and operatively Ydisposed v between .said electric inotorand said clamp,

and an electric'switchA for 'controlling/the operation of said motor, aiid'v a-control-mem,

bei` havingop'erative connection with said movable -ni'emberiand with ksaid switch `for arranging said couple:fon-connection and for operating-said lswitch for substantially full motor 'actuation by movement in vone direction et said control-member.

G. In adrilling machine, the combination Y ot a base, a tool-arm adjustable 'to radial positions thereabove, a clamp for clamping said tool-arm in adjusted position, means for operating said clampcomprising an electric motor, av mechanical power connecting and disconnecting couple lb etween said elecinclude mechanical connections with said clutchand said switch, said connection withY said switch lincluding `a spaced connection for retarding electric transmissionjby said i switch.

8. In adiill-ing machine,the combination of a base, a column rotatable onv said base, a drill-arm on said column, a clamp between saidcolumn and said base, meansior oper ating said clamp including a clutchand an electric switch, control means which include mechanical connections with said clutch and said switch, said connection with said switch includinga spaced connection for retarding electric transmission by said switch, and an automatic knock-out for said clutch.V

`9. Ina :drilling machine, the-combination oa base, a column rotatable on said base, adrill-a'rm on said column,.a clamp between said column and' said base, means for operating said Vclamp including a clutchaiid an electric switch, control'ineans which include mechanical connections with said clutch and said switch, said connection with said switchA including a *spacedl connection for retarding electric transmission by said switch, automatic clutch-engagingmeans, and an autoniaticvknocl-out for said clutch.

10.Y In a drilling machine, the combination of 4a base, atcol-arm adjustable to 'radial positions "thereabove, a Vclamp for clamping said -tool-arm in adjusted positions, said clamp including an eccentric, and meansfor rotating said eccentric comprising a cranks-having" operative connection with said -eccentricand arranged lto rotate said eccentricv in opposite directionsrespectively for clamp-ing and unclamping said clamp by rotationsin the samedirection of said cra-nk.V Y c y ,a

Y Ill. In a di'illing-machine,fthe combination of fa ibase, -a tool-arm adjustable lto radialpos-itions: thereabove, a clamp.. forv clamping. said tool-'arm in `adjusted positions, said clamp*includingan eccentric, means for rotating sain eccentric comprising,- a crank having operative connection with said eccentric land arranged to rotate said eccentric in opposite directions by rotations in the same direction of said crank, and .means causing cessation of rotation of said 4crank at each half-revolutionthereof.

12. In a drilling machine, the combination ot a base, a drill-arm adjustable to radial positions above said base, a clamp for clampingsaid drill-arm 'in adjusted positions including an eccentric, means 'for rorating said eccentric comprising a crank,

and means for interrupting the rotations of said crank alternately atpositions in which the anis of said crank is at opposite sides of its axis of rotation and at substantially dead-center"positionsfwith relation to the line'of clampingforce; v 'lSfIn-a drilling` machine, the combination of a base, a drill-arm adjustable .tol radial positions' thereabove, a clamp" 'for clamping said. drill-arniin adjusted positions, nieansi'or.`operating said clamp in-Y cludingra crank, a mechanical power con-v clamping said drill-arm in adjusted posi-y tions, ieans for operating saidciamp includingfacrank, a mechanical power cennecting and disconnecting couple, a knockvvont couple including a--knock-out member rotatable with said crank and a member having operative *connection with a member oi' said,Erst-named couple for disconnecting said first-named couple,cushioning` means for said knock-outcouple for ciishioninp,r the shock of Contact between said 'rotatable knock-ont member and its companion member oi'isaid second-named couple, and a stop for saidcushioning means;

l5. In aj drilling machine, the combina-V tion of a base, a drill-arm 'adjustable'` to radial positions above said'base, a clamp forY clamping said drill-arm in adjusted positions includingy an eccentric, means for rotating said eccentric comprising a crank, and means for rotating said crank and forinterrupting the rotation of said crank at substantiallj7 dead-center position with relation to the line of clamping force thereon dnring clamping position lof' said eccentric,

said means for rotating-said crank includ-f,

ing a mechanical power connecting and flisconnect-ing couple, and an` automatic knockout therefor. i

. ln a drillingl machine, the combinationy of a base, a `drill-arm Aadjustable to radialpositions thereabove,A a clamp for clamping saidfdrill-arnrin adjusted posi-v tion, means for operating said-clamp comprising a crank, knock-out means .rotating therewith, a mechanicalpower connecting` and disconnecting couple, a lever for ope-` ating the same, said knock-out means koper-V v ating said lever` to disconnect saidcouple,

Hand `a manual control means forroperating` said lever. ,l j l 17. In a drilling' machine, theI combination oi abase, .a drill-arm adjustable to radial positions thereabove, agclamp rfor clamping `.said drill-arm in .adjusted posi-r tion, means for operating said lclamp comprising a crank, Lknock-fout means. rotating therewith, a Vmechanical power connecting and disconnecting couple, a leverr for operating the'saine, means for resiliently vholding said lever for connected relation` ot'said couple, said knock-out means operating said,

lever to disconnect saidv couple, and a manualk control' means Yfor operating said. lever.'A lln a drilling machinepthe combination of a base, a drill-arm adjustablek to radial positions thereabove, a clamp for clamping said drill-arm in adjiistedposition, means for operating'said clamp com-V prising'v arotatable member having opera-y tive connection with said clamp' to clamp and unclamp the same, an Velectric motor, a power train between said electric motor and said rotatablemember comprising; speed reducing gearing and a mechanical power connecting and disconnecting couple,rand an automatic knock-out Jror saidcoiuple comprising a member having rotative connectionj-with said rotatable-,member Vand a member operated thereby having connec tion with a member of said couple for anto- 'matically disc'onnecting` said rcou ale.

19. ln a drilling"J machine, the combina-r tion of a base, tlg-rotatable" column thereon, a drill-arm on said column, a drill-head adjustable-laterally on'said drill-arm, a.

clamp for clamping said column'tosaid base wherebysaid arml is clampedV in radial position, ran.electric motor. for operating said clamp, a switch controlling the same, a .niechanical powerl connecting` and disconnecting-couple between said electric motor and said clamp, control'means below said arm for connecting,` said couple and operating said switch, and a Vmanually operated mem-` ber for said control-means havin operative connection with said drill-head or moving laterally therewith. j

20. In a drilling machine, the combinaiio ifoV

tion of a base, a drill-arm adjustable to radial positions thereabove, a clamp for vclamping said drill-arm in adjusted position, operating means for said clamp, an

electric motor, a mechanical power connectingand disconnecting couple between said electificinotor andv said operating means, a lever V:tor operating the same, resilient means forv maintaining the same inoperated position, knock-out means having operative connection withsaid operating means andl actingY on saidffleif'er 1 to disconnect said rcouple, and manual control means tor'connecting said* couple;V

"21. Ina drilling machine, the combination voil-a Ybase, a drill-arm adjustable to radial Ypositions thereabove, a clamp for clamping said drill-arm in adjusted position,'operatiiig ineansv for saidfclamp, an electric motor, a switch therefor, a mechanical-power Vconnecting vand disconnecting Y couplegbetween said electric motor and said o eratinof'means` a lever for o eratinfr the i v O Y? 3 ,sainefresilient means for maintaining the same jin operated position, knock-out means haviiigfoperative connection with said operatingmeans and 'acting oni said lever ,to disconnectV s aidA couple, and lmanual control Vmeansffor connecting said couple and operating said switch.

tiony of a base, rotatable column' thereon, a drill-arm on said column, a drill-head adjustable laterally on said 'drill-arm, a clamp for clamping'said' column to said base wherej by saidarm isclamped in Yradial posit-ion,

i )connecting with said switch. 5o

an electric motor forioperating said clamp, a switch controlling the same, a mechanical power connecting 'and disconnecting` couple between said'electric motor and said clamp,

a 'pair of links havingrco'nnections respectivelyV with said couple and said switch, a

manualV control means for combinedly operating saidilinks, said connection withv said couple comprising a latch, and a trip therefor `for permitting idle movement of said linkiconnecting withv said couple during continuino` operating movement g orp said link 23, In afdrillingv machine, the combinaytionfof a'base, a lrotatable column thereon,

a 'drill-arm on saidcolumn, a drill-head adjustable laterally on Ysaid drill-arm, a clamp for clamping said" column to said base whereby said arm is clamped in radial position, an electric motor for operating said clamp, a switch controlling the same, a mechanical power connecting and disconnecting couple between said electric motor 22. In a drilling ymachine,ithe combinaand said clamp, a pair of links having connections respectively with said couple and said switch, a manual control means for combincdly operating'said links, said connection with said couple comprising a latch, andV a trip. therefor for permitting idle vmovement oit said link connecting with said couple during continuing operating move# vment of said link connecting with said switch, 'said -manualcontrol means having operative connection withl said drill-head for movinglatera'lly therewith.

24. in a drilling machine, the combination of a base, a Vrotatable 'column thereon,

a drill-arm on said column, a drill-head adjustable laterally on ksaid drill-arm, a

clamp for c lampingsaid column to said base whereby said arm is clamped in radial position, an Velectric motor v for operating said clamp,v a switch controlling the same, ajniechamcal power connecting'aiid disconnecting couple between said electric motorV and said clamp, a pair of links having con;

nections respectivelyy withY said couple and said swit .'i, a :manual control means for comlunedly operating said links, said 'consoV nectioii with said couple comprising a latch, a

trip vtherefor for permitting idle movement ci said link. connecting with said couple during continuing operating vmovement o said link connecting with said switch, and automaticknock-out means for said couple.

25. ina drilling machine, the combination of a base a rotatable column thereon a drill-arm on said column, a drill-head adjustableA laterally on said drill-arm, a clamp tor clamping said column to said base whereby said arm is clamped in radial position, lan electric motor for operatingV said clamp, a switch controlling.V the same,r

a mechanical power connecting andfdisconnecting couple comprising la movable membei' between said electric" motor and said clamp, lan arm for operating said movable nember, means 4forresiliently'holding said arm in operated position, a Vlink having connection with said arm, a linkV having connection with said switch, ainanual 'means for combinedly operating said links, said connection with said arm including a latch, a trip therefor for permitting idle movement ot 'said iirst-nained link during continuingV 

